Windows 7 compatibily with Xp program

Windows 7 is the new OS by windows and programs such as known anti virus and internet securities are making their software version compatible with windows 7. But I already have Microsoft office 2007 installed on Xp and wonder if this will continue to work if I shift to windows seven. i don't want to buy another version of Office 2007 compatible with Win7, so please tell me if it will work or if there is any compatibility pack to download and install to make it work.Discussions on other programs working for WinXp and having or could have compatibility issues with Win7 is welcomed